Process for preparing lignite for fuel



s. M. DARUNG. PROCESSFOR PREPARING LIGNITE FOR FUEL.

APPLICATION FILED DEC. I, 1919.

Patented J une 28, 1921.

2 SHEETS-SHEET I.

S. M. DARLING.

PROCESS FOR PHEPARING LIGNITE FOR FUEL.

APPLICATION FILED 050.1. 1919.

1,382,629. Patented June 28, 1921.

2 SHEETS-SHEET 2.

I! I E @i vw..

m/ II II IIIIII/fv /TLIIHM IW III/7 PATENT OFFICE.

SAMUEL DARLING, -OF WASHINGTON, DISTRICT 0F COLUMBIA.

PROCESS FOR PREPARING LIGNITE FOR FUEL.

Specification of Letters Patent.

Patented June 28, 1921.

Application nled December 1, 1919. Serial 4No. 341,768.

To all 'whom t may concern: i l

Be it known that I, SAMUEL M. DARLrNG, a citizen of the United States, residing at lifashington, in the District of Columbia, have invented certain new and useful Improvements in Processes for Preparing Lignite for Fuel, of which the following is a specification.

This invention relates to a process of preparing lignite for fuel.

Large tonnages of lignite are found in parts of the United States which have no other solid fuel. This lignite is little used, and high prices are paid all over the lignite sections for imported bituminous coals. The

I reason forthis'is found inv certain physical characteristics of the lignite itself. As it lies in the ground it contains 30 to 40 per cent. water. The -necessity for the evaporation of this water in the stove or furnace is, of course, anfenormous handicap upon the fuel. When ythe lignite is mined and exposed lto warm air and sunlight, the evaporation of the water causes the coal to disintegrate or slake very rapidly it also fires very quickly from spontaneous combustion; hence it is not practicable to ship it long distances or to store it. Its light gases distil before the fixed carbon reaches the temperature of ignition and, in the ordinary furnaces, escape unconsumed. The lignite has no coking quality whatever, and when thrown upon Vthe fire crumbles very quickly, giving rise to difficulties in tiring and substantial loss through the grate bars.

My methods of preparation eliminate all of these objections tothe lignite as a fuel.

When prepared according to my process, as

hereinafter described, the fuelis' free from Water, it will not slake or disintegrate 1n any condition of weather; it is free from the danger of spontaneous combustion; 1t can be burned readily without loss in stoves and furnaces; and it can be stored for any length of time and shipped any distance without deterioration. In fact, when so prepared 1t is the equivalent in` all respects of good bituminous and anthracite coals, and w1ll supersede the use of these fuels in the sections of the country tributary to these llgnite' deposits.

The accompanying drawings illustrate a preferred apparatus by which my process ma be carried out. I

1bn the accompanying drawings Figure 1 1s `a sectional View taken through the furnace,

and

Fig. 2 is a rear elevation.

In accordance with my process I combine lignite with pitch, or pitch and coal and briquet the resulting mixture. The briquets are then placed in a retort or oven and heated. The degree of this vheating may be merely carried to a point at which the Volat1le matter in the pitch binder of the briquet is distilled off or may be carried to the point o f complete carbonization of the briquet. In elther event the by-products passing off in the form of gases are recovered. The lignite may be in itsraw condition, 1n which state it contains a high percentage of water and light Volatile gases and oils, dr or carbonized.

ere the lignite is combined with pitch alone, I prefer to mix the pitch with the lignite in about the proportions of 8 to 10 per cent. pitch and 90 to 92 per cent. lignite. The pitch may be that derived from coal tar, water gas tar, lignite tar or any other similar hydrocarbon or as haltic pitch. The lignite is preferably pu verized and then combined with the pitch. This mixture is thenv briqueted in the usual way and the .of the volatile matter in the pitch and to coke it. The pitch coke is thus thoroughly disseminated throughout the briquet and serves to hold it together in all Weathers and under all reasonable methods of handling. The lignite as previously stated may be combined with the pitch either in' a raw, dried or carbonized state, and While Ihave stated above that the lignite briquet is heated to 700 Fahrenheit, in some instances it may be ldesirable to carry the heat to a ointat which the briquet is. completely car onized.`

After passing through the heating chamber the briquets are placed in a cooling chamber and the volatile matter which has been distilled therefrom is passed over the briquets. Some of this volatile matter condenses upon the surfaces of the briquets and V has the quality of improving their appear\ ance and heating value and rendering the briquets Weather and waterproof;

Where thel lignite is combined withpitch and coal I prefer to mix the ingredients in about the following proportions:

8 per cent. pitch,

12 per cent. coal,

80 per cent. dried lignite.

This mixture is then briqu'eted in the usual manner and the briquets are* placed within a sealed container retort or oven and the temperature thereof raise-d by means of heat externally applied to the point of intumescence of the bituminous coal or about 700 Fahrenheit,l as is the case where the raw lignite is combined withpitch. This heating operation serves to dry the lignite and distil off the volatile matter in the pitch. The briquets are subsequently cooled and are preferably treated with the volatile gases as above explained. The pitch coke and intumesced bituminous matter are thus thoroughly disseminated throughout the briquet and serve to hold it together, forming a very 'strong briquet and one having a great crushing strength.

The lignite may be combine-d with the pitch and coal either in a raw, dry or carbonized condition` andthe briquts may be either heated to the point of intumescence of the coal or this heating may be carried to -the point of complete carbonization of the briquet.

Referring now to the drawingslthe numeral 10, indicates a furnace as a whole, having fire boxll. In the present instance this fire box is shown as being provided upon its upper surface with an opening 12 through whichfuel may be supplied' to the 'grates 13 thereof.

Arranged Iin the combustion chamber of the furnace are inclined ovens or retorts 15 provi-ded at their upper ends with gates 16. and at their lower ends with gates 17. It

f is to be noted that approximately one-half of each of the retorts projects beyond the rear wall of the furnace.- Upon the front of the furnace is arranged a suitable traveling carrier 18, provided with chutes 19 opening adjacent to the doors 16 upon the upper ends of the inclined retorts. Adjacent to their lower ends and without the furnaces the rctorts 15 are provided Vwith collector pipes 20, for the purpose of carrying off the gases formed by volatile matters within the retort.

These pipes are connected with a header 21 which may inturn be connected with any suitable condensing apparatus, or the volatile gases may be lead into the furnaces and 'burned as desired.

Arranged about the lower en d of the inclined retorts without the furnace is a chamber 22 having an air inlet pipe 23 and an the pipe 23 being connecte-d with any suitable source of air pressure supply.

In practising the process, the briquets are placed in the traveling container 18 and distributed `by means of:` the chutes 19 to the various retorts 15. The briquets are heated within the upper ends of the retorts or that lportion lying within the furnace to the desired temperature andare then allowed to pass to the lower end of the retort or that It is to be understood that the above disclosure is the preferred method of practising the fprocess but that various changes may be made in the detailsof procedure and proportions of materials employed and that I4 do not limit'myself to the exact disclosure set forth, but that various changes may be made without departing from the spir1t of the invention or 4the scope of the subjoined claims.

What I claim is:

1. The herein described process for preparing lignite for use as fuel consisting of mixing Vthe lignite with pitch in the proportions of 8 to 10 parts of pitch `to 80 to 82 parts of lignite, briquet-ing the mixture, heating the briquets to distil ofr` volatile matter therein in the form of gases and cool- 3. The herein described process of preparing lignite for use as fuel, consisting in mixing the lignite with pitch and coal in approximately the proportions of 8 per cent. pitch 12 per cent. coal and 80 per cent. 11gnite, briqueting the mixture, and heating the briquets to distil off volatile matter therein andrv collecting thc gases given oil' by such volatile matter.'

In testimony whereof I aix my signature in presence of two witnesses.

SAMUEL M. DAR-LING. Witnesses:

JOHN B. WA'rKINs,` JOHN L, PRoUDFooT.. 

